Emergency electric plant



L. c. FRANK ET Al. 2,063,994

EMERGENCY ELECTRIC PLANT Filed June 14, 1954 V fea f ;llllllllIlllrlWITNESSES: INVENTORS eo c. fPQnA/mc 57E/Mey /7 Babe.

Patented Dec. 15, 1936 UNITED STATES PATENT OFFICE EMERGENCY ELECTRICPLANT Application June 14, 1934, Serial No. 730,628

Claims.

This invention relates to power plants and more particularly to powerplants utilized in conjunction with a source of power so as to providecontinuous service to certain current-consuming 5 devices.

In theaters there are certain current-consuming devices which arenormally utilized in the operation of the theater and still othercurrentconsuming devices, such as the lights illuminating exits, aislelights and others which are disposed for the protection of the occupantsof the theater. Normally, all such current-consuming devices aresupplied with energy from a source of alternating current. However, incase of failure of the source of supply provision must be made toproperly illuminate aisle lights, exit lights and certain othercurrent-consuming devices to protect the patrons.

At airplane landing iields a number of currentconsuming devices areusually utilized but where the landing eld is used for regular nightservice, it is very necessary that the flood lights to illuminate thelanding area be in service regardless of the condition of the normalsource of supply for the landing field. It is thus very necessary thatan emergency power plant be held in readiness in case of failure of themain source of supply, which emergency power plant may be set inoperation to illuminate the ood lights.

An emergency power plant thus has utility in theaters, landing fields,beacons indicating air lanes, as well as light houses and possibly manyother places where it is Very essential that certain current-consumingdevices remain in service regardless of the power failure from the usualsource of supply.

One object of this invention is to provide for selectivelyinterconnecting certain current-consuming devices in load systems withsources of power.

Another object of this invention is the provision of an emergency powerplant in conjunction with the usual source of supply, and 'the selectiveinterconnection of certain current-consuming devices with the emergencypower plant and the usual source of supply.

A still further object of this invention is to provide for automaticallydisconnecting certain current-consuming devices from a source of supvply, the voltage of which has failed, and connecting saidcurrent-consuming devices to a second source of supply.

A still further and more specic object of this invention is theprovision of means responsive to the voltage of a source of supply forconnecting certain current-consuming devices to said source of supplyand for effecting the connection of said current-consuming devices toanother source o1 supply when the voltage of said firstnamed source cisupply decreases below a certain 5 value.

Other objects and advantages will become more apparent from a study ofthe single iigure illustrating this invention, which single figure showsdiagrammatically an emergency power plant in 10 cooperative relationwith the usual source of supply.

Generally considered, this invention embodies an internal combustionengine 30 having the usual ignition system 29 which is adapted to be 15disconnected, or short-circuited, by the closing of either one of a pairci switches or contact members SI and i8. The engine is provided with a,mechanical governor t5, although any other kind of governor may bereadily used. 20

In the particular installation shown, the internal combustion engine issupplied with energy from a tank (not shown) containing gasoline or anyother liquid fuel and to assist in the vaporization of the fuel, aheater 54 and a choke valve 25 5E are provided.

The internal combustion engine when in operation drives a direct-currentgenerator 43 which is adapted to be interconnected with a battery I I tooperate as a motor to crank the engine when 30 certain current-consumingdevices 2l are to be disconnected from a source of alternating currentdesignated by the mains l and 4 and are to be connected to thedynamo-electric machine 43 which is to be operated as a generator by the35 internal combustion engine. The starting system for the internalcombustion engine is provided with a thermostatie cranking cut-out I3, astarting contactor t8 and a reverse current relay 36 for effecting theconnection of the current-con- 40 suming devices 2l to the generator 43when the voltage of this generator has attained a desired value afterthe starting of the internal combustion engine. The transfer of thecurrent-consuming devices 2l from the mains I and 4 to the 45 generatori3 is eiiected by an appropriate operation of the voltage-responsivedevice 9.

A better and more complete understanding of this invention can probablybe had from a study of a typical transfer sequence when it is as- 50sumed that the voltage on the mains I and 4 fails. Assume :lirst thatthe mains I and 4 are energized at the desired voltage, whereupon anenergized circuit is established from main I through primary winding 2of the transformer 3 55 to the main 4. The secondary winding 5 of thetransformer 3 is thus energized and a circuit is established from theupper or positive terminal of the double wave rectiiier B through thestop switch a, actuating coil 3 of the voltage-responsive transfercontacter Q, conductor IIJ, the battery il, series heater I2 of thetherinostatic cranking cut-out relay i3, and conductor I4 to thenegative terminal of the double-wave rectier 5. This circuit just tracednot only causes the operation of the transfer contactor 9 but alsoprovides for a continuous trickle charge for the battery I I from thesource of alternating current through the rectifier 5.

Operation of the transfer' contactor 9 closes the contact members l5, 2iand 2U and opens the contact members 32. This operation thus establishesa circuit from the main I through contact members l5, conductor i5,current-consuming devices I, conductors i8 and I9, and contact members2S to the main 4. The current-consuming devices i? are of thenon-emergency type that need not be energized in the event of a voltagefailure of the main source of supply, namely, a failure of the voltageacross the mains I and 4.

A further circuit is established from the positive terminal or therectifier 5 through the stop switch l, contact members 2i, actuatingcoil 22 of the line contacter 23 and conductor 24 to the negativeterminal of the rectiiier 6. Actuating coil 22 is designed to havesuiiicient ampere turns to overcome the effect of the high reaotanceholding coil 'ill of the line contacter 23, Which holding coil le issuitably energized from the direct current dynamo-electric machine 43 tohold contact members 25 and 28 open during the operation of thedynamo-electric machine 43. The details of this operation will becomeclearer in the discussion given hereinafter.

The operation of the line contacter 23 by rcason of the energization ofthe actuating coil 22 establishes a circuit from the main I throughcontact members I5 and 25, conductor 26, current-consuming devices 2i,and conductor I8 to the energized conductor I9. The current-consumingdevices 22 are devices such as iiood lights on landing iields or exitlights and aisle lights in theaters, which must remain energizedregardless of the failure of the voltage across the mains I and 2.

Assume that the voltage across mains I and 4 fails, which, of course,means that the voltage across the positive and negative terminals of therectier E will also become zero, thereby deenergizing the coils 3 and 22of the transfer contactor S and line contactor 23, respectively.Current-consuming devices I7 Will, of course, be deenergized by reasonof the voltage failure across the mains I and 4, whereas thecurrent-consuming devices 2l will be temporarily deenergized by theopening of the ,circuit for the devices at the contact members 25 byreason of the deenergization of the actuating coil 22.

The deenergization of the transfer contacter 9 causes the opening ofcontact members I5, 20 and 2i, thereby disconnecting the load lines andalso the actuating coil 22 from the mains I and 4. rlhe closing ofcontact members 32, however, establishes a circuit from the positiveterminal of the battery through conductor I0, contact members 32 of thetransfer contactor II, contact members or the thermostatic crankingcutout relay l5, conductor 34, contact members 35 of the reverse currentrelay 38, actuating coil 31 of the starting contacter 38, and seriesheater I2 of the relay I3 to the negative terminal of the battery.

The operation of the starting contactor 38 establishes a circuit for theshunt heater 39 of the relay I3 through the Contact members 40, and thestarting circuit is also established from the energized conductor Ithrough conductor 4I, armature 42 of the dynamo-electric machine 43,series eld Winding 44, series coil 45 of the reverse current relay 35,contact members 46 and heater I2 to the negative terminal of the batteryI I. A further circuit is also established for the shunt coil 52 of thereverse current relay 36, this circuit being established through theresistor 50 and the Contact members I connected in parallel.

Under normal operation, the engine will start to operate, but if for anyreason the engine should fail to operate, the heaters I2 and 3B wouldcontinue to be energized and after a predetermined cranking interval thethermostatic clement 65 would move in such a position that the endthereof would pass into the aperture G8 and the spring 6'1 would openthe contact members 33, thereby disconnecting the dynamo-electricmachine from the battery to discontinue any further cranking Withoutsome attention on the part of the attendant to investigate the source ofthe trouble.

Assuming that the engi .e 3U starts, the dynamo-electric machine 43 willthus be caused to operate as a generator and the motoring current in thecoil 45 will decrease to zero and, in consequence, the reverse currentrelay 3E will be caused to operate. Prior to the generator operation ofthe dynamo-electric machine 43, coils 45 and 52 were energized in such amanner as to oppose each other and this reverse current relay 36 isthereby prevented from operating prior to the starting of the engine andto a predetermined rise in the generator voltage of the dynamo-electricmachine 43. it will be noted that the coil 52 is connected across theterminals of the dynamoelectric machine 43 and is energized in the samedirection as it was energized previously from the battery I I. However,the current through coil 45 is reversed.

Before there is any appreciable rise in the current in coil 45, thereverse current relay 36 will be caused to operate to open its contactmembers 35 and 5I and to close its contact members 63. Opening of thecontact members 5I merely inserts the resistor 59 directly in circuitwith the coil 52 to decrease the continuous current that this coilthereafter consumes, Whereas the opening of contact members 35 opens thecircuit for the actuating coil 3".' of the starting contacter 38, whichcontacter thereupon opens the Contact members 46 to disconnect thebattery II from the generator 43 and also open the circuit for the shuntheat-er 39 of the cranking cut-out relay I3.

During the starting operation, it is, of course, desirable to properlyvaporize the gasoline passing to the internal combustion engine 30 andalso to increase the relative amount of fuel supplied to the internalcombustion engine. This is accomplished by the circuit established fromthe energized conductor IG through contact members 32, contact members33 of the relay I3, conductor 34, contact members 35, conductor 53, fuelheater 54 and actuating coi 55 of the choke 5S, connected in parallel,and conductor 5T to the negative terminal of the battery. The opening ofthe contact members 35 also interrupts the circuits for the elements 54and 55 just mentioned, thereby no longer heating the fuel passingthrough the generator 43 from the conductors internal combustion engineand decreasing the fuel supply to the normal quantity needed.

As the Voltage of the generator 43 rises, an energized circuit isestablished from the conductor I through actuating coil 58 of thecontactor 59 and conductors E0 and 6I and series field 49 to thenegative terminal of the generator 43. It will be noted that therheostat 41 and shunt eld 48 are also connected across the terminals ofthe generator 43.

Operation of the contactor 59 establishes a circuit from the positiveterminal of the generator 43 through conductors 4I and I0, contactmembers 64, conductor I8, current-consuming devices 21, conductors 26and 62, contact members 63, conductor 6I and series field 49 to thenegative terminal of the generator 43. Since conductors I8 and 26 areenergized from the generator 43, the holding coil of the line contactor23 is thus energized from the generator and thus maintains contactmembers 25 and 28 open so as not to remove the effective ignitioncircuit for the internal combustion engine 38.

When the power or the voltage returns on the mains I and 4, thetransformer 3 is, of course, again energized, and the normal voltageagain appears at the positive and negative terminals of the rectifier 6.The circuit heretofore traced for the actuating coil 8 of the transfercontactor 9 is again established and in consequence, conductors I6 andI8 are connected directly to mains I and 4 and the actuating coil 22 ofthe line contactor 23 is energized to oppose the effect of the holdingcoil 1D. As heretofore explained, the effect of coil 22 is of sufficientstrength to overcome the action of coil 10, thereby closing the contactmembers 25 to connect the current-consuming devices 21 to the mains Iand 4 and also causing the snorting out of the ignition system 29 forthe internal combustion engine 38 by the f closing of the contactmembers 28. Since the voltage of the generator 43 decreases, thecontactor 59 is deenergized and contact members 84 are opened. Furtherthe energization of coil 52 ceases and, in consequence, contact members63 are opened, thereby completely disconnecting the I8 and 26. However,by the closure of contact members 35, the emergency power plant is againput into such position that a second failure of voltage on the mains Iand 4 will again start the transfer cycle by again starting theemergency power plant and also by disconnecting the current-consumingdevices 21 from the mains I and 4 and connecting these current-consumingdevices to the generator 43 operated by the internal combustion engine30.

Applicants are aware of the fact that others skilled in the art,particularly after having had the benefit of the teachings of thisinvention, can devise other circuit diagrams and automatic transfermeans for accomplishing the novel results hereinbefore set out andclaimed in the appended claims. Applicants do not Wish to be limited tothe specific circuit arrangement shown, but wish to be limited only bythe scope of the claims.

We claim as our invention:

1. In an electric system, a consuming circuit, a source of alternatingcurrent, a line contactor, a relay responsive to the voltage of saidsource adapted to energize said contactor to connect and disconnect saidconsuming circuit with the source of alternating current, a directcurrent dynamo-electric machine, a battery, an internal combustionengine, a starting contactor, means operable by said relay to cause theoperation of said starting contactor to connect said machine to drivesaid engine, means responsive to the generator action of said machine todeenergize said starting contactor to disconnect the battery from themachine, and means responsive to the generator action of said machine toconnect said consuming circuit to said machine.

2. In an electric system, a consuming circuit, a. source of alternatingcurrent, a rectifier connected to said source, a line contactor, a relayconnected to the. rectier and thus responsive to the voltage of saidsource adapted to energize said contactor from said rectifier to connectand disconnect said consuming circuit with the source of alternatingcurrent. a direct current dynamoelectric machine, a battery, an internalcombustion engine, a starting contactor, means operable by said relay tocause the operation of said starting contactor to connect said machineand the battery to drive said engine, means responsive to the generatoraction of said machine to deenergize said starting contactor todisconnect the battery from the machine, and means responsive to thegenerator action of said machine to connect said consuming circuit toSaid machine.

3. In an electric system, a consuming circuit, a source of alternatingcurrent, a rectifier connected to said source, a line contactor, arelay, connected to the rectier to be responsive to the voltage of saidsource, adapted to energize said contactor from said rectifier toconnect and disconnect said consuming circuit With the source ofalternating current, a direct-current dynamoelectric machine, a battery,means for connecting said battery to said rectier to charge the batteryfrom said source, an internal combustion engine, a starting contactor,means operable by said relay to cause the operation of said startingcontactor to connect said machine to the battery to drive said engine,means responsive to the generator action of said machine to deenergizesaid starting contactor to disconnect the battery from the machine, andmeans responsive to the generator action of said machine to connect saidconsuming circuit to said machine.

4. In an electric system, a consuming device, a source of alternatingcurrent, a source of direct current, said sources being adapted to beconnected respectively to supply energy to said device, a rectifier,means, connected to the rectifier to be responsive to the voltage ofsaid source of alternating current, adapted to disconnect said devicefrom said source of alternating current, and means, responsive to thevoltage of said direct-current source of power, adapted to connect saiddevices to said source of direct-current power.

5. In an electric system, in combination, a load circuit, a source ofpower connected normally to supply energy to said load circuit, astand-by power plant comprising an internal combustion engine, agenerator, a battery, means adapted to cause said battery to be chargedfrom said source of power, means responsive to a failure of Voltage ofsaid source of power to cause the starting of said engine todrive thegenerator and to disconnect said load circuit from said source of power,and means responsive to a certain voltage of said generator to connectsaid load circuit to said generator.

LEO C. FRANK. STANLEY A. BOBE.

